Synopsis

PDX_MSGT gdx_GetSurfaceNumSegs(long option, void *gdx_surface, long *num_u_segs, long *num_v_segs)

Purpose

Retrieves the number of segments in u, v for a given surface.

Description

Given a GDX surface, determines the number of segments in each of the u and v directions. If the surface is defined using a curve generatrix, the number of segments is taken from the curve for the corresponding direction. Segments are defined as follows:

GDX entity	Segment Determination
–
GDX_NURB_SURF	Segments in u and v taken from distinct knot
	values corresponding knot vectors (taking bounds
	into consideration)
GDX_SPLINE_SURF	Segments in u and v taken from the nusegs and nvsegs
	fields, respectively.
GDX_RULED_SURF	Segments in u derived from ruling curves (max
	for the 2 ruling curves). The number of segments in
	the v direction is 1.
GDX_REV_SURF	Segments in u derived from generatrix curve. The
	number of segments in the v direction is determined
	using the basis that each quarter circle is 1
	segment.
GDX_EXT_SURF	Segments in u derived from generatrix curve. The
	number of segments in the v direction is 1.
GDX_PLANE	The number of segments for each of the u and v
	directions is set to 1.
GDX_CYLINDER	The number of segments for the u direction is set
	to 4. The number of segments in the v direction is
	set to 1.
GDX_CONE	The number of segments for the u direction is set
	to 4. The number of segments in the v direction is
	set to 1.
GDX_SPHERE	The number of segments for each of the u and v
	directions is set to 4.
GDX_TORUS	The number of segments for each of the u and v
	directions is set to 4.
GDX_OFFSET_SURF	The number of segments in each direction is taken
	from the base surface
GDX_RECT_TRIM_SURF	The number of segments in each direction is taken
	from the base surface

Input

option

Options (not used)

gdx_surface

Entity structure pointer of the GDX Surface

Output

num_u_segs

The number of u segments

num_v_segs

The number of v segments

Tolerances

      KNOT_TOL
      ANGLE_TOL
      .fi

Return

      GDX_NOERR
      Low level error return
      .fi